Harnessing microbial potential: Exploiting heavy oil-laden soil microbiota for sustainable production of high-yield rhamnolipids from waste cooking oil

Oil polluted soil microbiota plays an important role in the production of biosurfactants. In comparison to synthetic surfactants, biosurfactants offer unique advantages, such as lower toxicity, biodegradability, selectivity, and effectiveness under unpleasant conditions. Despite these benefits, the widespread use of biosurfactants is limited by enormous production costs. To address this challenge, this study aimed to explore the adoption of waste cooking for rhamnolipids production. Two prominent bacterial strains: Kosakonia cowanni and Acinetobacter colcoaceticus, were obtained from heavy oil-laden soil samples, and further demonstrated their capability for rhamnolipids production from waste cooking oil ( Acinetobacter colcoaceticus : 0.51 g/L, Kosakonia cowanii : 0.39 g/L). The biosurfactants obtained were characterized through TLC, FTIR, and H NMR to confirm their rhamnolipid identities as mono-rhamnolipids. The findings in our study emphasizes the potential of cost-effective production of rhamnolipids that possess interesting biotechnological features through the synergy of oil-polluted environments and waste cooking oil. This study contributes significantly to the development of sustainable rhamnolipid production using non-pathogenic strains. By harnessing these microorganisms, we advance towards addressing critical environmental challenges, such as heavy metal contamination in water. This research aligns with broader sustainability goals, including clean water and sanitation. • The earliest production of rhamnolipid by Kosakonia sp. was elucidated. • Waste cooking serves as an excellent feedstock for rhamnolipid production. • The secretion of mono-rhamnolipids was confirmed by NMR, FTIR and TLC.